ATDH Biology Exam Questions and
Correct Answers| 2026
Cell membrane
Hold cellular components and are mainly composed of phospholipids, cholesterol,
and proteins
Organelles
Cellular compartments enclosed by phospholipids bilateral (membrane bound)
Are located within the cytosol (aqueous intracellular fluid) and help make up the
cytoplasm
Only eukaryotes contain membrane-bound organelles
Nucleoid
Where prokaryotes keep their genetic material
Nucleus
Primarily functions to protect and house DNA
DNA replication and translation occurs here
,Nucleoplasm
Cytoplasm of the nucleus
Nuclear envelope
Membrane of the nucleus
Contains two phospholipid bilayers with a perinuclear space in the middle
Nuclear pores
Holes in the nuclear envelope that allow molecules to travel in and out of the
nucleus
Nuclear lamina
Provides structural support to the nucleus, as well as regulating DNA and cell
division
Nucleolus
Dense area that is responsible for making rRNA and producing ribosomal subunits
,Ribosomes
Work as small factories that carry out translation
Composed of ribosomal subunits
Rough er
Continuous with the outer membrane of the nuclear envelope and is "rough"
because it has ribosomes embedded in it
Lumen
Inside of the rough er
Smooth er
Not continuous with other membranes
Main function is to synthesize lipids, produce steroid hormones, and detoxify cells
Golgi apparatus
Made up of cisternae (flattened sacs) that modify and package substances
, Lysosomes
Membrane-bound organelles that break down substances (through hydrolysis)
taken in through endocytosis
Transport vacuoles
transport materials between organelles
Food vacuoles
temporarily hold endocytosed food and later fuse with lysosomes
Central vacuoles
Very large in plants and have specialized membrane called the tonoplast
Function in storage and material breakdown
Storage vacuoles
store starches, pigments, and toxic substances
Correct Answers| 2026
Cell membrane
Hold cellular components and are mainly composed of phospholipids, cholesterol,
and proteins
Organelles
Cellular compartments enclosed by phospholipids bilateral (membrane bound)
Are located within the cytosol (aqueous intracellular fluid) and help make up the
cytoplasm
Only eukaryotes contain membrane-bound organelles
Nucleoid
Where prokaryotes keep their genetic material
Nucleus
Primarily functions to protect and house DNA
DNA replication and translation occurs here
,Nucleoplasm
Cytoplasm of the nucleus
Nuclear envelope
Membrane of the nucleus
Contains two phospholipid bilayers with a perinuclear space in the middle
Nuclear pores
Holes in the nuclear envelope that allow molecules to travel in and out of the
nucleus
Nuclear lamina
Provides structural support to the nucleus, as well as regulating DNA and cell
division
Nucleolus
Dense area that is responsible for making rRNA and producing ribosomal subunits
,Ribosomes
Work as small factories that carry out translation
Composed of ribosomal subunits
Rough er
Continuous with the outer membrane of the nuclear envelope and is "rough"
because it has ribosomes embedded in it
Lumen
Inside of the rough er
Smooth er
Not continuous with other membranes
Main function is to synthesize lipids, produce steroid hormones, and detoxify cells
Golgi apparatus
Made up of cisternae (flattened sacs) that modify and package substances
, Lysosomes
Membrane-bound organelles that break down substances (through hydrolysis)
taken in through endocytosis
Transport vacuoles
transport materials between organelles
Food vacuoles
temporarily hold endocytosed food and later fuse with lysosomes
Central vacuoles
Very large in plants and have specialized membrane called the tonoplast
Function in storage and material breakdown
Storage vacuoles
store starches, pigments, and toxic substances
